EP0668213B1

EP0668213B1 - Packaging film feeding and splicing apparatus and method

Info

Publication number: EP0668213B1
Application number: EP95107241A
Authority: EP
Inventors: Howell Tyson Mcelvy
Original assignee: Kliklok LLC
Current assignee: Kliklok LLC
Priority date: 1993-03-12
Filing date: 1993-12-29
Publication date: 1997-07-16
Anticipated expiration: 2013-12-29
Also published as: EP0614809B1; EP0668213A2; DE69311695D1; DE69312313D1; EP0668213A3; ES2102612T3; EP0614809A3; ES2104445T3; DE69311695T2; US5388387A; EP0614809A2; DE69312313T2

Description

The present invention relates to feeding film into a form, fill and seal packaging machine and, more particularly, to continuous film feeding that eliminates interruptions associated with loading a new supply roll of film.
Assemblies and methods for unwinding and feeding of packaging film into a form, fill and seal packaging machine are known in the art. A number of other machines that process web material similar to film, such as printing presses, employ similar feeding assemblies and methods. These feeding assemblies typically include means for supporting and unwinding a supply web roll and means for feeding the web into the processing machine.
In the case of a form, fill and seal packaging machine, the film is ultimately formed into an open package, filled with a product, and sealed to retain the product until opened for use. A wide variety of products, most notably food items, are packaged in this manner. To further explain, the basic combination of a form, fill and seal packaging machine is disclosed in U.S. Patent 4,727,707, assigned to the assignee of the present invention. It discloses a method and assembly for controlling the feed of packaging film from a supply roll over a former, where the film is formed into an open tube. A filling means provides a measured amount of product into the bottom of the tube where a package or bag is being formed. The package is then sealed across the top to yield a filled, hermetically sealed package with the product on the inside (see Figures 2-4). The '707 patent actually covers a particular improved control routine for film registration utilizing registration marks detected by a photoelectric cell and triggering the various form, fill and seal operations.
It is desirable to minimize the down-time of the packaging machine so that a maximum number of packages or bags can be produced during each unit time. This necessarily means that not only is a reliable high speed package forming, filling and sealing operation required, but also a reliable high speed film feeding/registration arrangement is a necessity, as illustrated in the '707 patent.
In prior art assemblies, film is typically supplied for feeding along the feed path into a form, fill and seal portion of the machine by loading or installing a roll of the film on a spindle or web roll cradle, and controllably rotating the roll to unwind the film. A significant disadvantage of these prior art packaging film unwinding arrangements is the lost operating time caused during change-over when a roll of film is exhausted and a new roll must be loaded and brought on stream. this change-over typically requires an operator to stop the packaging machine to load a new roll of film on the spindle or cradle, thread the film along the feed path and then restart and regulate the machine operation. Typically, lost machine production time is between 10-30 minutes.
The potential lost operation time can be further magnified because a single operator is, in many instances, required to keep several machines operating simultaneously. Thus, if two or more machines require a new roll to be loaded at about the same time, or an emergency occupies the operator's attention at a time when a new roll of film is required, the interruption and lost operating time are detrimentally increased.
Some prior art feeding assemblies and methods have sought to correct or alleviate this problem by incorporating dual roll supporting and unwinding equipment so that upon exhaustion or expiration of an active roll, the threading of the film from a standby roll can begin immediately. This reduces the roll change-over interruptions because the operator can have the standby roll pre-loaded in the machine. Thus, the overall down-time of the packaging machine is reduced.
Some web feeding approaches for other types of machines have suggested going a step farther to include a provision for automatically splicing the tail-end of the web of the active roll to the head-end of the web of the standby roll so that the web is truly continuously fed without any roll change-over interruption.
In these web feeding assemblies and methods, it is highly desirable to include provision for implementing the splicing by a control means upon detection of the tail-end of the web of the active roll being at a splice position along the feed path. In addition, upon expiration of the active roll of the web and its release from the spindle, there must be provisions for maintaining tension on the web. This is necessary to maintain tracking of the web through the machine and to ensure that the tail-end is properly orientated to be spliced upon reaching the splice position.
When successful, this splicing operation alleviates much of the problem of a single operator trying to keep several machines operating simultaneously. It can result in minimizing, and indeed, eliminating roll loading and change over interruptions. The operator has a much wider window of time within which to load new rolls on the machines without risking interruption and lost operating time. In theory, an operator merely installs a new roll onto the standby spindle at any time during unwinding of the active roll prior to its expiration, and the machine can continue operating indefinitely without interruption.
Examples of prior art methods and assemblies for feeding webs supplied on rolls into processing machines and including such splicing provisions are to be found in US Patents 4,455,190; 4,722,489 and 4,880,178.
A problem associated with such prior art feeding assemblies and methods that include splicing provisions is the subsequent processing and handling of the head-end/tail-end splice section. That is, the splice section must be retained along the feed path throughout the entire processing machine to maintain the continuous web until the final cut-off point in the process. It is desirable to track the splice section through the entire machine, to inhibit further processing of it, and to recognise it at the cut-off point and dispose of it. Prior assemblies and methods have not addressed the problems of tracking the splice section through the machine to inhibit its processing, and/or to remove it after cut-off. Inhibiting the processing of the splice section is referred to as operating the machine in a "dry cycle mode".
Accordingly, it is a primary object of the present invention to provide an improved form, fill and seal packaging machine, overcoming the above described limitations and disadvantages of the prior art by providing a splicing assembly and method where it is possible to track the splice section through the machine and to inhibit its processing and to ultimately dispose of it.
It is another, and related objective to provide an assembly/method for splicing two rolls of a film for a form, fill and seal packaging machine so that the splice section and any tail is as short as possible to minimise waste.
According to the present invention, therefore, a form, fill and seal packaging machine includes a splicing assembly to allow substantially continuous feeding of packaging film with registration eye marks spaced apart on the film and from at least two rolls, comprising means for supporting and unwinding an active and a standby roll of film to the machine, each roll having a head-end and tail-end of its film; means for substantially continuously feeding film along a feed path from the active roll into and through the machine; means for splicing the tail-end of the active roll to the head-end of the standby roll, the splicing means creating a recognizable splice section in the film; forming means applied to form the film into packages; sealing means applied to seal each package; machine drive means for synchronously actuating the forming means and the sealing means; and filling means applied to fill each formed package with product; characterised by control means for coordinating the machine drive means and the product filling means to provide a series of sealed packages containing the product and a dry cycle at the splice section, whereby all completed formed, filled and sealed packages are acceptable.
The assembly of the present invention specifically includes means for alternatively supporting and unwinding an active roll of film and a standby roll of film and means for substantially continuously feeding and controlling the film of both rolls. Opposed pneumatic means applies first a vacuum source to hold the head-end of the film of the standby roll and attached adhesive tape at the splicing station and, further, to provide constant tension on the film of the active roll at the splicing station, at least during the travel as the tail-end approaches. The pneumatic means rapidly switches at the proper time to apply a positive pressure source producing a controlled air blast that blows the head-end of the film of the standby roll toward the tail-end of the film of the active roll so that the tail-end sticks to the adhesive on the head-end. A control circuit, including a programmable controller, performs the rapid switching of preferably one, or in some instances, both of the pneumatic means from vacuum to positive pressure.
Still other objects of the present invention will become apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the modes best suited to carry out the invention. As it will be realised, the invention is capable of other different embodiments and several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.

Figure 1 is a schematic side view of an assembly for substantially continuously feeding packaging film to a form, fill and seal packaging machine embodying features of the present invention.
Figure 2a is a partial schematic side view of the film feeding assembly including the splicing station and showing the tail-end of the active roll film after leaving the spindle and being tensioned by the drag shoe;
Figure 2b is an enlargement of the splicing station of Figure 2a and illustrating the relative position of the two films;
Figure 3a illustrates the splicing station just after the tail-end of the active roll film activates the end of film detector initiating application of the vacuum source to the manifold to provide the tension on the active roll film;
Figure 3b is an enlargement of the splicing station of Figure 3a and also showing the initiation of the counting of the bag lengths remaining on the active film;
Figures 3c and 3d compliment the showing of Figures 2a and 3a by illustrating in more detail the operation of the drag shoe and the end-of-film detector;
Figure 4a and 4b are partial schematic side views of the assembly at the point in the cycle when the encoder counts up to the next to last eyemark on the film of the active roll, at which time positive pressure is applied at the manifold adjacent the head-end to generate an air blast and blow the head-end toward the tail-end to splice them together;
Figure 5 is a side view enlargement of the splicing station illustrating the pivotal mounting of the opposed pneumatic manifolds for film tensioning/holding that allows easy alternate loading of the head-end of the film of the standby roll; and
Figure 6 is a plan view of one of the pneumatic manifolds for film tensioning/holding and illustrating the oppositely threaded rods engaging dam members that define the effective width of the manifold.

Reference is now made to Figure 1 schematically illustrating an assembly 10 for substantially continuously feeding packaging film into a form, fill and seal packaging machine M. The film feeding assembly 10 includes a splicing station 11 and relevant components of a control circuit C. An active roll 12 of film 14, and a standby roll 16 of film 18 are shown as a part of the feeding assembly 10. As will be described further herein, the novel means for splicing the two films together is provided at the splicing station 11. While the preferred embodiment of the invention is described with respect to packaging film, it is understood that in accordance with its broader aspects, other types of indeterminate length webs can be spliced using the novel principles. This is particularly true with respect to relatively thin, plastic and composite webs.
The active roll 12 is installed on and unwound from a spindle 20 so that the film 14 is substantially continuously fed along the feed path, indicated by the arrows P. The standby roll 16 is similarly installed on a spindle 24. As shown in Figure 2a, the active roll 12 is unwound until its tail-end E₁ of the film 14 leaves the spindle 20. Thereafter, the tail-end E₁ is pulled along the feed path defined by idler guide rollers rolls R₁, R₂ until it reaches the splicing station 11. The two rolls 12, 16 are alternately the active and standby rolls; and accordingly, a description is provided for only the mode of operation where the roll 12 serves as the active roll, as shown in Figures 1 and 2a. It is to be understood that as the rolls 12, 16 alternate between the active/standby status, the operation is basically the same, so that a single detailed description and corresponding reference numerals are appropriate. As described, the roll 12 is the active roll and the roll 16 is the standby roll (see Figure 1).
Upon reaching the splicing station 11, the tail-end E₁ is tensioned by a first pneumatic means or manifold 32 and spliced to the head-end E₂ of the film 18. As a result, the film 14, 18 is substantially continuously fed without interruption into the machine M along the feed path P defined by rollers R₁-R₅ (see Figure 1). The roller R₄ forms a film driving nip with opposed roller R₆. This roller couple, or similar couple, keeps constant tension on the film 14, 18 along the feed path P, and serves to turn the corresponding spindle 20, 24 during normal feed operation. After completing the splice, the new film 18 from the standby roll 16 continues to be fed along the path for packaging.
The film 18 of the standby roll 16 is prepared to be spliced by simply holding the head-end E₂ at the splicing station 11. Specifically, this is accomplished by roughly trimming the head-end E₂, applying single-sided adhesive tape T and placing the tape so that its non-adhesive side is held on a second pneumatic means or manifold 34. This is done by applying suction from a vacuum source 35 (see Figure 1). The tape T has its adhesive side facing upwardly toward the film 14 (see Figure 2b). The head-end E₂ covers and adheres to approximately one-half of the exposed adhesive side of the tape T. Subsequent application of a controlled blast of air from a pressure source 38 to the second pneumatic means 34 sufficiently blows the head-end E₂ along with the exposed half of the adhesive side of the tape T so that it adheres to the tail-end E₁ to complete the splice. The positive pressure source 38 to generate the air blast is applied through line 39 and valve 44. The vacuum source 35 is applicable through the same control valve 44 in a similar manner through line 36.
As mentioned above, the driven rollers R₄, R₆ provide tension in the web 14 during normal operation, that is as long as the active roll 12 remains. As soon as the tail-end E₁ is released from the spindle 20 (see Figure 2a) the tension is maintained by a brake shoe 40 acting against the roller R₁ (see Figure 2a). Alternatively, the brake shoe 40 can be replaced by a brake roller as an option. As illustrated, the tail-end E₁, may terminate at an eyemark 42 that is printed on the film 14 itself. Note in Figure 2a, as well as the other figures, the spacing of the eyemarks 42 which identify individual bags. In reality, the eyemarks 42 are located at an intermediate point along the bags for the purpose of control of the packaging machine M, and as more fully set forth in the '707 patent, as mentioned above.
To complete the tensioning function, once the tail-end E₁ is pulled from between the brake shoe 40 and the roller R₁ (see Figures 3c-3d), a microswitch 45 having a feeler that rides on the film 14 drops into a groove 46, which in turn activates the valve 44 to provide suction at the pneumatic means or manifold 32. This action, which will be explained more in detail below, provides for tensioning of the film 14 at least adjacent the tail-end as the splicing station 11 is approached (see Figures 3a and 3b).
As will be realized, the microswitch 45 is connected by an electrical line 47 to a programmable controller 48, which components are a part of the control circuit C. As illustrated, the programmable controller 48 through a line 49 is what controls the valve 44. At the moment the microswitch 45 is triggered (see Figures 3c-3d) the valve 44 for the manifold 34 is operative to switch to the vacuum line 36 in order to provide the suction required to attract the film 14 and apply tension at the splicing station 11, as best shown in Figures 3a, 3b. This action is particularly advantageous, and as will be seen in further detail below, since the tension is now directly applied where the splicing function occurs. As will be apparent to those skilled in the art, the programmable controller 48 can be selected from any one of a number of off-the-shelf controllers having sufficient capabilities of operating from a number of input signals and controlling a number of operating mechanisms.
Once the tail-end E₁ of the film 14 reaches the splicing station 11, in a precise manner as explained below, the controller 48 is operative to switch the valve 44 for the manifold 34 from the vacuum line 36 to the positive pressure line 39. In response to this triggering action, the pressure source 38 generates a blast of air to positively, but controllably, blow the head-end E₂ toward the tail-end E₁ of the active film 14 from the roll 12 (see Figures 4a, 4b). In accordance with the invention, the flow of air is sufficient to force the head-end E₂ into firm contact with the tail-end E₁ so as to cause said tail-end E₁ to stick to the adhesive tape T. At this moment, the film 18 of the standby roll 16 is securely spliced to the film 14 of the previously active roll 12 to provide film feeding to the packaging machine M that is substantially without interruption and without slowdown. Furthermore, the splicing action is carried out without the deleterious effect of forcefully slapping the film together by mechanical elements, which in the past caused problems of machine maintenance and the tendency to burst the film.
As another part of the control circuit C, there is provided a spindle control 50 to make certain that the speed of the web 14 of the active roll 12, as well as the speed of the film from the standby roll 16 Substantially matches the speed of the film 14, 18, respectively, as it progresses along the feed path P (see Figure 1). As presently contemplated, the spindle control 50 may include positive braking/driving means to accomplish this purpose. While it is possible to momentarily interrupt the feeding of one or both of the films 14, 18, it is highly desirable to provide substantially continuous operation by incorporating the spindle control 50 with braking and/or positive drive.
As best shown in Figures 5 and 6, the pneumatic means/ manifolds 32, 34 preferably takes the form of a manifold plate 55 with spaced openings 56 through which the suction/blast of air is alternately applied. The manifolds include an elongated housing 57 and inlet ports/tubes 58 (see also Figures 2b, 4b). As indicated above, the inlet ports/tubes 58 are connected to the valve 44 through a suitable connection, and serve to provide the suction/blast of air as required for the film final tensioning/holding function, and the splicing operation.
As best shown in Figure 6, the elongated housing 57 is in two sections and each includes means for adjusting the effective width W of each manifold plate 55; the width W corresponding to the width of the film 14, 18 that is being spliced, and which is used to form the package or bag, as will be seen in more detail below.
In particular, the adjusting means for each manifold plate 55 includes a pair of dam members 60, 61 that slide along the inside on opposite sides in the longitudinal direction (note the motion arrows in Figure 6). As is apparent, the opposed dam members 60, 61 limit or direct the suction/positive pressure to the central portion of each section of the housing 57 to control the films 14, 18, as described. Adjustment rod 62 for each pair of the dam members 60, 61 are oppositely threaded from central connecting sleeve 63, and thus upon rotation by suitable manual wheels 64, 65 geared to rotate together, the rod 62 is effective to cause opposite linear translation of the dam members 60, 61. In this manner, once the manifold plate 55 is properly adjusted to the width W of the films, there is no loss of vacuum or positive pressure.
In order to provide easy operator accessibility to the manifold plate 55, in order to load the head-end E₂ and the tape T as a standby roll 16 is being readied for feeding, a pair of arms 70, 71 are provided for mounting at pins 72 from stationary frame member F of the feeding assembly 10 (see Figure 5). The arms 70, 71 support the manifold plate 55, as well as the idler guide roller R₂. As illustrated, once the arms 70, 71 are being released and pivoted to the open or loading position, the head-end E₂ and a tape T can be easily installed. An over center spring 75 can be provided for each arm 70, 71 in order to provide a convenient manner of positioning and securing the arms in either the operative or the loading positions (see the full line and the dotted line positions in Figure 5).
As will be realized, the operator that loads the standby roll 16 is provided with a mechanism by which the task is easily performed as the manifold plate/ housing 55, 57 forming either pneumatic means/ manifold 32, 34 is easily switched between positions. To position the arms 70, 71 at the proper locations, spaced stops 77, 78 are provided. As illustrated, these stops are positioned relative to the pivot pin 72 so that the spring 75 goes over center, that is across the pivot pin 72 and thus locates and holds the manifold plate 55 in the proper relative position for loading, or for operation (compare the dotted line loading position at 70° from the horizontal, to the full line horizontal position for operation).
With reference back to Figure 1, the additional functions of the programmable controller 48 within the control circuit C can be explained. The additional functions are generally dependent on the spaced eyemarks 42. First, a photoelectric cell 80 is connected by line 81 to the programmable controller 48. It is positioned just downstream from the splicing station 11 to read the spaced eyemarks 42 (see, for example, Figures 2a, 2b). In addition, an encoder 85 including a linear measuring wheel 86 is included in the circuit C and connected by the line 87 to the controller 48.
In operation, as soon as the tail-end E₁ triggers the end of film microswitch 45, the controller 48 is programmed to accept the linear measurement from the encoder 85. Previously, the predetermined distance from the splicing station 11 to the tail-end E₁ is programmed in the memory of the controller 48. This distance can be any distance that assures splicing before the tail-end passes the splicing station, but is preferably the distance between the eyemark 42 at the splicing station, and the next to last eyemark 42, as shown in Figure 2a.
The photocell 80 now senses the eyemark 42 and the measurement commences. Once the encoder wheel 86 senses this length of the film 14 passes (such as three bag lengths of film as shown in Figure 3a), the controller 48 initiates the splicing operation. In other words, once the first signal for the arrival of the eyemark 42 at the photocell 80 after the end-of-film signal is sent from the microswitch 45, the splicing location is determined by the encoder 85. In the example, it is set by the machine as three bag lengths. The splice is always adjacent the eyemark 42 and the center of the bag lengths of film 14, 18 so that the later cut-off in the packaging machine is clean.
At the appointed time, the valve 44 for the manifold 34 rapidly switches from the vacuum source 35 to the pressure source 38, thereby providing the blast of air to blow the head-end E₂ and the tape T and splice the films 14, 18 together. As illustrated, once the predetermined distance is determined, such as three bag lengths as illustrated, the splicing can occur in a timed and efficient fashion without intervention by the operator. Of course, in certain instances where the tail-end E₁ is cut-off at less than a full bag length, the final eyemark 42 is the one that is adjacent the splicing station 11 (approximately under the photocell 80) when the splicing operation occurs. In either case, a minimum length of the tail-end E₁ on the film 14 remains in order to minimize the waste.
With reference now back to Figure 1, more detail of the packaging machine M can be given. Thus, a photocell 100 is positioned to read the same eyemark 42 in order to provide a signal to the controller 48 for operation of the components of the machine M. More particularly, a product filling means 101 is activated in timed relationship to dump a charge of product P, such as potato chips, through a filling tube 102. The web 14 is tensioned and pulled around the tube 102 and over a former by endless belts 103, which in turn are substantially continuously driven by a servo machine drive 104 that is timed in a conventional manner from the controller 48. In addition to the feed belts 103, the machine drive controls the operation of sealing jaw/cut-off knife 105 and the oscillation of the carriage 106 to form the series of packages or bags. Since the programmable controller 48 utilizes the same eyemarks 42 to control the machine M as it does to control the feeding assembly 10, the entire operation can be appropriately synchronized and coordinated, and the entire film feeding and packaging operation can be most efficiently carried out. However, in some instances such as for retrofit applications dual programmable controllers may be employed and they are networked together.
The photocell 100 provides input signals to the controller 48, which in turn counts the predetermined number of bag lengths between the splicing station 11 and package forming station 110 in the packaging machine M. At the point when the overlapping film tail-end E₁ and head-end E₂ sections that form the spliced section of the films 14, 18 arrive at the packaging forming station 110, as indicated by the count, a dry cycle is initiated by inhibiting the product filling means 101. In this manner, only one overlapping bag section of the overlapping films 14, 18 is discarded, no product is involved and thus the waste is minimized.
In practising the method of the present invention for substantially continuously feeding packaging film, the first requirement is to mount the two rolls 12, 16 in the feeding assembly 10 for sequentially unwinding in order to form a substantially continuous flow of packages or bags, each said roll having a head-end and a tail-end. The film 14 that is being actively unwound substantially continuously feeds along the feed paths into the packaging machine M. The next step is applying adhesive means, such as the tape T, to the head-end E₂ of the film 18 of the standby roll 16 as it is being held on the pneumatic means/manifold 34. Tensioning of the active film 14 along the feed path P is provided at least adjacent the tail-end E₁ by the pneumatic means/manifold 32.
Finally, positive pressure is provided at the splicing station 11 to generate an air blast with sufficient air flow to blow the tail-end/head-end of the films together and provide the splicing function by causing the tail-end to stick to the adhesive means. As a result, the film of the standby roll is securely spliced to the film of the active roll to provide film feeding substantially without interruption and without slow down.
In the method, it is also important to detect the tail-end E₁ of the film 42 of the active roll 12 at a detection point along the feed path P as it approaches the splicing station 11. Upon detection, the tensioning step is initiated, such as providing suction to the pneumatic means/manifold 32 (see Figure 3b).
In order to ensure interference free loading of the film 18 of the standby roll 16, it is important to provide a loading station L spaced a substantial distance from the splicing station 11. Applying the head-end E₂ is performed at the loading station L (see Figure 5).
In another important aspect of the method, eyemarks 42 are provided at spaced locations along the film 14, 18. These eyemarks are positioned at approximately a midpoint between the designated seal areas of the package/bag. As the tail-end E₁ is detected (see Figure 3d), the eyemarks on the film 14 are sensed by the photocell 80 at a position just downstream of the splicing station 11. The length of film 14 remaining at that time (such as three-bag lengths) between the splicing station 11 and the tail-end E₁ is premeasured and stored in the memory of the programmable controller 48.
The encoder/wheel 85, 86 is instrumental in calculating the length of film and thus the number of eyemarks remaining in the film 14 until the tail-end E₁ reaches the splicing station 11. Rapidly switching the pneumatic means/manifold 32 from a suction mode to a positive pressure mode thus occurs to make certain that splicing operation takes place while at least some remaining film is on the tail-end E₁. However, since the splicing occurs adjacent the next to last/last eyemark 42, the packaging film 14 to be discarded is minimized.
Once the splice is made at splicing station 11, it is important that the section with the splice is tracked through the system to the packaging machine M. Since the splice is made at the midpoint of a bag section of the films 14, 18, it is known that this limited film is the only waste. More specifically, in the method, by preprogramming, the controller 48 is set so that there is a known mumber of bag sections or eyemarks 42 from the splicing station 11 through to the bag forming station 110. The photocell 100 keeps track of the number of eyemarks 42 (see Figure 1) and at the point when the spliced bag section arrives at the bag forming station 110, the product filling means 101 is inhibited by the signal from the controller 48 so that the product P is not fed into the tube 102. The sealing jaws/knives 105 operate to cut out the splice bag section, and it is discarded from the stream of acceptable formed, filled and sealed packages. As a result, not only is the amount of film 14, 18 that is wasted minimized, but none of the product P is wasted in the operation accordingly to the present invention.
It will be realized at this point in the operation of the feeding assembly 10 and the packaging machine M that the roll 16 on the spindle 24 and the film 18 now becomes active, and the spindle 20 is now empty. An appropriate signal is provided to the operator and he promptly provides a new roll 12 of the film 14, which now becomes the standby roll. The operator simply pivots the arms 70, 71 supporting the pneumatic means/manifold 32 to the dotted line loading position, shown in Figure 5, prepares the head-end of the film 14, and suction is provided to hold the new head-end and the adhesive tape in position. The arms 70, 71 are then pivoted about the pivot support 72 to the ready position at the splicing station 11, and the entire process of splicing the film 14 to the now active film 18 is ready to proceed, in accordance with the same procedure as described above.
In summary, the film feeding assembly 10 and the related method provides substantial results and advantages over the prior art approaches. The active/ standby films 14, 18 are automatically spliced together in a substantially continuous manner. There is no need for an operator to standby and interrupt the packaging machine M in order to load a new roll of film. A substantial window for loading the new, standby roll is provided as the active roll is being fed and packages are being formed in a continuous manner. A single operator can now take care of many more machines without difficulty.
In a novel manner, the programmable controller 48 controls the feeding assembly 10, as well as the packaging machine M, and coordinates the operations to perfection. Advantageously, the splice section is efficiently formed at the splicing station 11 by a blast of air that causes the head-end E₂ of the standby roll 16 to be blown against the tail-end E₁ of the active roll 12. Thus, there are no mechanical parts that are forced together and cause a slapping of the webs. The maintenance problems of the past and potential rupture of the films 14, 18 are alleviated. When the film of the one of the rolls 12, 16 is depleted, the operator has easy access to the pneumatic means/ manifold 32, 34 by simply swinging the appropriate one to a loading station L (see Figure 5). Finally, the amount of discarded packaging film 14, 18 at the spliced section is minimized due to the ability to efficiently track it through the feeding assembly 10 and the packaging machine M. At the point when the splice section arrives at the packaging forming station 110, only this single section is removed, and no product P is included.

Claims

A form, fill and seal packaging machine (M) including a splicing assembly (10) to allow substantially continuous feeding of packaging film (14) with registration eyemarks (42) spaced apart on the film and from at least two rolls, comprising:-
means for supporting and unwinding an active and a standby roll (12,16) of film (14,18) to the machine (M), each roll having a head-end (E₂) and tail-end (E₁) of its film;

means for substantially continuously feeding film (14) along a feed path (P) from the active roll (12) into and through the machine (M);

means for splicing the tail-end (E₁) of the active roll (12) to the head-end (E₂) of the standby roll (16), the splicing means creating a recognisable splice section in the film (14);

forming means applied to form the film (14) into packages;

sealing means applied to seal each package;

machine drive means (104) for synchronously actuating the forming means and the sealing means; and

filling means (101) applied to fill each formed package with product;
characterised by:-
control means for coordinating the machine drive means (104) and the product filling means (101) to provide a series of sealed packages containing the product and a dry cycle at the splice section (11),

whereby all completed formed, filled and sealed packages are acceptable.
A packaging machine and splicing assembly as in Claim 1, characterised in that the control means comprises:-
a programmable controller (48); and photocell means (80, 100) for sensing the eyemarks.
A packaging machine and splicing assembly as in Claim 1 or 2, characterised by:-
adhesive means (T) on the head-end (E₂) of the film (18) of the standby roll (16).
A packaging machine and splicing assembly as in any one of Claims 1 to 3, wherein the splicing means includes:-
first pneumatic means (32) for tensioning the film (14) of the active roll (12) at least adjacent the tail-end (E₁); and

second pneumatic means (34) opposed to the first pneumatic means (32) for holding the head-end (E₂) and the adhesive means (T) at a splicing station (11) adjacent the feed path (P);
characterised by:-
the pneumatic means (32, 34) including a vacuum source (35) to provide suction for the tensioning and holding functions and a pressure source (38) to generate an air blast to blow the tail-end and head-end (E₁, E₂) of the respective film (14, 18) towards each other; and

control means (44) for rapidly switching one of the pneumatic means (32, 34) between the vacuum source (35) and the pressure source (38);

the pressure source (38) providing sufficient air flow to cause the tail-end (E₁) to stick to the adhesive means (T);

whereby the film (18) of the standby roll (16) is securely spliced to the film (14) of the active roll (12) to provide film (14) feeding to the machine (M) substantially without interruption and without slow-down.
A method of continuously feeding, splicing and tracking packaging film (14) into and through a form, fill and seal packaging machine forming a series of filled packages, comprising the steps of:-
supporting and unwinding an active and a standby roll (12, 16) of film (14, 18), each said roll having a head-end (E₂) and a tail-end (E₁) of its film (14, 18);

continuously feeding the film (14) of the active roll (12) along a feed path (P) into the machine (M);

splicing the tail-end (E₁) of the film (14) of the active roll (12) to the head-end (E₂) of the film (18) of the standby roll (16) substantially without stopping movement of the film (14) along the feed path (P);

creating a recognisable splice section where the tail-end (E₁) and the head-end (E₂) are spliced;

tracking the splice section through the machine (M); and

forming, filling and sealing each completed package;
characterised by the steps of:-
generating a dry cycle mode of the machine (M) when the splice section is positioned at the package forming and filling station of the machine (M); and

removing the splice section from the series of completed packages,

whereby all completed formed, filled and sealed packages are acceptable.
A method as in Claim 5, characterised by the additional steps of:-
applying adhesive means (T) to the head-end (E₂) of the film (18) of the standby roll (16);

holding the head-end (E₂) and the adhesive means (T) at a splicing station (11) adjacent the feed path (P);

tensioning the film of the active roll (12) along the feed path (P) at least adjacent the tail-end (E₁) of the film (14) of the active roll (12); and

rapidly applying positive pressure at the splicing station (11) to generate sufficient air flow to below the tail-end and head-end (E₁, E₂) of the respective films (14, 18) together to cause the tail-end (E₁) to stick to the adhesive means,

whereby the film (18) of the standby roll (16) is securely spliced to the film (14) of the active roll (12) to provide film feeding to the machine (M) substantially without interruption and without slow-down.
A method as in Claim 6, characterised by the additional step of:-
providing a manifold (32, 34) at the splicing station (11) for receiving the head-end (E₂) with the adhesive means (T) in overlapping relationship; and

applying a vacuum through the manifold (32, 34) to at least the head-end (E₂).
A method as in Claim 7, characterised in that the film (14) includes registration eyemarks (42) and characterised by the additional steps of:-
detecting eyemarks (42) on the film (14) at a position proximate to the splicing station (11);

detecting the tail-end (E₁) of the film (14) of the active roll (12) at a detection point along the feed path (P) approaching a splicing station (11);

measuring the length of film (14) fed along the feed path (P);

calculating the number of eyemarks (42) remaining in the film (14) until the tail-end (E₁) of the active roll (12) reaches the splicing station (11); and

rapidly switching from the application of the vacuum to the step of applying the pressure upon detection of the next to last eyemark (42).